Initial commit: agentic chat app for IBM Storage Scale REST API v3

Adds a Python package that wraps the Storage Scale /scalemgmt/v3 management
API behind a Claude-driven tool-use loop. Ships a Rich-styled terminal REPL
and a Streamlit web UI sharing the same Agent/Dispatcher/GPFSClient stack.

Guardrails are env-driven (.env): read-only by default; writes and DELETE
gated by GPFS_ALLOW_WRITES / GPFS_ALLOW_DESTRUCTIVE; optional path
allow/deny regex; mutating calls require operator confirmation. Free-text
GPFS_INSTRUCTIONS (or GPFS_INSTRUCTIONS_FILE) appended to the system prompt.

The system prompt also includes a curated v3 endpoint reference compiled
from IBM Storage Scale 5.2.3 / 6.0.0 documentation so the agent doesn't
have to guess endpoint shapes for common operations.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

gpfs_agent/config.py

@@ -0,0 +1,106 @@
+from __future__ import annotations
+
+import os
+import re
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Optional, Pattern
+
+from dotenv import load_dotenv
+
+
+def _bool(name: str, default: bool = False) -> bool:
+    raw = os.getenv(name)
+    if raw is None or raw == "":
+        return default
+    return raw.strip().lower() in {"1", "true", "yes", "on", "y"}
+
+
+def _required(name: str) -> str:
+    val = os.getenv(name)
+    if not val:
+        raise RuntimeError(
+            f"Missing required env var {name}. Copy .env.example to .env and fill it in."
+        )
+    return val
+
+
+def _optional_pattern(name: str) -> Optional[Pattern[str]]:
+    raw = os.getenv(name)
+    if not raw:
+        return None
+    try:
+        return re.compile(raw)
+    except re.error as exc:
+        raise RuntimeError(f"Invalid regex in {name}: {exc}") from exc
+
+
+@dataclass(frozen=True)
+class Config:
+    anthropic_api_key: str
+    model: str
+    max_tokens: int
+
+    gpfs_base: str
+    gpfs_username: str
+    gpfs_password: str
+    verify_tls: bool | str
+    timeout: float
+
+    allow_writes: bool
+    allow_destructive: bool
+    confirm_mutations: bool
+
+    path_allow: Optional[Pattern[str]] = None
+    path_deny: Optional[Pattern[str]] = None
+    extra_instructions: str = ""
+
+    @property
+    def allowed_methods(self) -> set[str]:
+        methods = {"GET"}
+        if self.allow_writes:
+            methods |= {"POST", "PUT"}
+        if self.allow_writes and self.allow_destructive:
+            methods.add("DELETE")
+        return methods
+
+
+def load_config(env_file: Optional[Path] = None) -> Config:
+    if env_file is not None:
+        load_dotenv(env_file, override=False)
+    else:
+        load_dotenv(override=False)
+
+    verify_raw = os.getenv("GPFS_VERIFY_TLS", "true").strip().lower()
+    ca_bundle = os.getenv("GPFS_CA_BUNDLE")
+    if ca_bundle:
+        verify: bool | str = ca_bundle
+    elif verify_raw in {"0", "false", "no", "off", "n"}:
+        verify = False
+    else:
+        verify = True
+
+    instructions = os.getenv("GPFS_INSTRUCTIONS", "").strip()
+    instructions_file = os.getenv("GPFS_INSTRUCTIONS_FILE")
+    if instructions_file:
+        path = Path(instructions_file)
+        if path.is_file():
+            file_text = path.read_text(encoding="utf-8").strip()
+            instructions = f"{instructions}\n\n{file_text}".strip() if instructions else file_text
+
+    return Config(
+        anthropic_api_key=_required("ANTHROPIC_API_KEY"),
+        model=os.getenv("ANTHROPIC_MODEL", "claude-sonnet-4-6"),
+        max_tokens=int(os.getenv("ANTHROPIC_MAX_TOKENS", "4096")),
+        gpfs_base=_required("GPFS_API_BASE").rstrip("/"),
+        gpfs_username=_required("GPFS_USERNAME"),
+        gpfs_password=_required("GPFS_PASSWORD"),
+        verify_tls=verify,
+        timeout=float(os.getenv("GPFS_TIMEOUT", "30")),
+        allow_writes=_bool("GPFS_ALLOW_WRITES", False),
+        allow_destructive=_bool("GPFS_ALLOW_DESTRUCTIVE", False),
+        confirm_mutations=_bool("GPFS_CONFIRM_MUTATIONS", True),
+        path_allow=_optional_pattern("GPFS_PATH_ALLOW"),
+        path_deny=_optional_pattern("GPFS_PATH_DENY"),
+        extra_instructions=instructions,
+    )